Organ preservation programs will be enhanced by our knowledge of cellular changes during ischemia and by the prevention of these changes. The aim of this project is to define changes in nuclear RNA metabolism caused by renal ischemia during organ storage. Mouse kidneys will be used with the test kidney flushed and stored at 0 or 37 degrees in different solutions for varying lengths of time. Also, in vivo ischemia will be produced in the rabbit by transfemoral catheter obstruction of the renal artery. Isotope techniques will aid in following the effects of ischemia on previously synthesized RNA. The ability of isolated nuclei to synthesize RNA and the molecular weight size of that synthesized RNA will be determined. Gel electrophoresis techniques will be used to determine molecular weight size of RNA. Nuclear chromatin will be isolated and assayed as template with exogenous RNA polymerase added. The size of the DNA template will be determined by low shear viscometry. The biochemical changes that are found to occur during organ storage may be useful to assay new methods of organ preservation. The pathways which are altered during organ storage may give clues as to areas which, if modified, will improve organ storage.